.pic {
    height: 360px
}

#slider {
    width: 800px;
    height: 374px;
    perspective: 800px;
    float: left;
    cursor: pointer;
    overflow: hidden;
    background-color: #333;
}

.pic li {
    list-style-type: none;
    height: 360px;
    width: 200px;
    float: left;
    position: relative;
    transform-style: preserve-3d;
    transform: translateZ(-180px)
}

.pic li div {
    height: 360px;
    position: absolute;
}

.pic li div:nth-child(1) {
    top: -360px;
    transform-origin: bottom;
    transform: translateZ(180px) rotateX(90deg);
    background: url('../images/1.jpg');
}

.pic li div:nth-child(2) {
    top: 360px;
    transform-origin: top;
    transform: translateZ(180px) rotateX(-90deg);
    background: url('../images/2.jpg');
}

.pic li div:nth-child(3) {
    transform: translateZ(180px);
    background: url('../images/3.jpg');
}

.pic li div:nth-child(4) {
    transform: translateZ(-180px) rotateX(180deg);
    background: url('../images/4.jpg');
}

.but li {
    list-style-type: none;
    width: 12px;
    height: 12px;
    border: 2px solid #fff;
    border-radius: 50%;
    line-height: 20px;
    float: left;
    margin: 0 4px;
    cursor: pointer;
}

.but {
    position: absolute;
    bottom: 10px;
    right: 10px
}

.but .active,
.but li:hover {
    background-color: #fff;
    cursor: default;
}